X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Fhtable%2Fhtable.h;h=03193567d847a5512b31d173bcb8a21a6d54d09e;hp=938b43afc89ce5a6603c45761da17d26b748475e;hb=HEAD;hpb=d615e534e870a911f11b7b88021242220ea053bf

diff --git a/ccan/htable/htable.h b/ccan/htable/htable.h
index 938b43af..faaf541b 100644
--- a/ccan/htable/htable.h
+++ b/ccan/htable/htable.h
@@ -75,6 +75,15 @@ bool htable_init_sized(struct htable *ht,
 		       size_t (*rehash)(const void *elem, void *priv),
 		       void *priv, size_t size);
 
+/**
+ * htable_count - count number of entries in a hash table.
+ * @ht: the hash table
+ */
+static inline size_t htable_count(const struct htable *ht)
+{
+	return ht->elems;
+}
+
 /**
  * htable_clear - empty a hash table.
  * @ht: the hash table to clear
@@ -123,7 +132,7 @@ bool htable_copy_(struct htable *dst, const struct htable *src);
  * htable_add - add a pointer into a hash table.
  * @ht: the htable
  * @hash: the hash value of the object
- * @p: the non-NULL pointer
+ * @p: the non-NULL pointer (also cannot be (void *)1).
  *
  * Also note that this can only fail due to allocation failure.  Otherwise, it
  * returns true.
@@ -258,6 +267,19 @@ void *htable_prev_(const struct htable *htable, struct htable_iter *i);
 	htable_delval_(htable_debug(htable, HTABLE_LOC), i)
 void htable_delval_(struct htable *ht, struct htable_iter *i);
 
+/**
+ * htable_pick - set iterator to a random valid entry.
+ * @ht: the htable
+ * @seed: a random number to use.
+ * @i: the htable_iter which is output (or NULL).
+ *
+ * Usually used with htable_delval to delete a random entry.  Returns
+ * NULL iff the table is empty, otherwise a random entry.
+ */
+#define htable_pick(htable, seed, i)					\
+	htable_pick_(htable_debug(htable, HTABLE_LOC), seed, i)
+void *htable_pick_(const struct htable *ht, size_t seed, struct htable_iter *i);
+
 /**
  * htable_set_allocator - set calloc/free functions.
  * @alloc: allocator to use, must zero memory!